Annual % of total
1960 95.91280653950955
1961 95.57291666666667
1962 95.75596816976127
1963 94.93975903614458
1964 94.824016563147
1965 94.0630797773655
1966 94.3157894736842
1967 94.45471349353049
1968 95.89041095890411
1969 95.17684887459808
1970 95.2153110047847
1971 95.34534534534535
1972 95.12855209742895
1973 94.75655430711612
1974 94.98207885304659
1975 94.48491155046827
1976 93.24473975636766
1977 93.5576923076923
1978 93.78330373001775
1979 93.90625
1980 93.739837398374
1981 92.79112754158966
1982 91.30434782608695
1983 91.118800461361
1984 92.92604501607717
1985 92.50780437044746
1986 90.58473736372645
1987 82.55280073461891
1988 89.77777777777777
1989 89.2055267702936
1990 107.77061068702292
1991 107.0982382133995
1992 109.78223602484472
1993 99.46109589041097
1994 114.53465930018416
1995 103.48447244094487
1996 98.33957996768983
1997 105.92311450381679
1998 96.56285886610374
1999 98.65124390243902
2000 88.8332696390658
2001 90.34800203873597
2002 84.58266475644699
2003 82.00302656546489
2004 85.10851162790698
2005 83.08046875000001
2006 82.7066203301477
2007 80.31350523771152
2008 77.61381672597865
2009 85.13010126582277
2010 76.1583056768559
2011 75.3078109028961
2012 73.52108641975309
2013 70.38046887009992
2014 69.8175770609319
2015 64.56523255813954
2016 62.27179266895762